Problem: Simplify the following expression: ${-4(-4x-1)-(-4+x)}$
Explanation: Distribute the ${-4}$ into the first set of parentheses: $ {-4(}\gray{-4x-1}{)} - (-4+x) $ $ {16x+4} - (-4+x) $ The minus sign in front of the parentheses means we multiply each term inside the parentheses by ${-1}$ $ 16x+4 {-1(}\gray{-4+x}{)} $ $ 16x+4 + {4-x} $ Rewrite the expression to group the ${x}$ terms and numeric terms: $ {16x - x} + {4 + 4}$ Combine the ${x}$ terms: $ {15x} + {4 + 4}$ Combine the numeric terms: $ {15x} + {8}$ The simplified expression is $15x+8$